Signaling system



July l5, 1929 A. LE BOUTILLIER Y A 1.720.738 I SIGNALING SYSTEM FiledDec. 16, 1926 MA RGV/VAI Patented July 16, 1929.

11 UNITED STATES 1,720,738 PATENT oFFIcE.-

AUSTIN LE IBOUTILIiIER, F WESTERN SPRINGS, ILLINOIS, ASSIGNOE, TOWESTERN ELECTRIC COMPANY, INCORPORATED, OF YORK, N. Y., A CORPORATION OFNEW YORK.

SIGNALING SYSTEM.

Application led December 16, 1926. `Serial No. 155,216.

' This invention relates to a signaling system, and more particularly toa signaling system yfor indicating a current failure in A, l a leadv ofa supply circuit.V An object of the invention is to provide a signaling`system` which `will indicate when jan electrically operated Adevice isnot operating atA its highest 'eificiency. Y i The inventioncontemplatesthe provision of means associated with each of a plurality offleads ofasupply circuitV to indicate when Aa total orpartial/failure of currentloccurs therein. Inaccordance with one embodiment, a series transformeris placed in each of the leads ,of a supply circuit to indicate fafailurevof current therein anda relay responsive to the currentin thetransformer for operating a signaling circuit isconnected acrosstheterminals ofa coil of a magneti- 2cally operated switchin the supplycircuit vto prevent an indication in the signal element -whenthe coil isdeenergized and the current infa predetermined numberV of leadsis'interrupted bythe normal operation ofthe switch. 2 Itis believed thata complete understanding of theinvention may be had by reference to the.following description taken in conjunction with the accompanyingdrawing, in which asignaling system is diagrammatical- 3.0 `1y4represented as applied to an' electric annealing furnace. y c

Referring to the drawing, a three phase line of alternating current 3,4, 5 is shown leadingthrough a main switch 6 through `fuses 7, 8,l 9 tothe primary of a transformer 10 which is provided with three secondaries`11` 12, "13 whichY supply'secondary circuits 14, `15and 16,respectively. The secondary circuits lead to deltaV connected heatingele- A ments 17, 18` and 19 of any suitable type which maybke-associated with an electric annealing furnace. AIt is customary infurnaces of vthis type to provide a plurality of heating-elements whichare located in vario ous parts ofthe furnace. The heating `element 17 inthe present instance is diagrammatically represented as'connected to the`seconda-ry circuits through movable elements such as `shoes V21engaging tracks for the Lreason that one of the heating elements is inmany instances located in the car in which @the material to beannealedis carried into the furnace.r Y f f The-secondary circuits 14,15 .and 16 are provided with'switches 2 2, 23 and 24 which are operatedby electro-magnetic coils 25,l 26 and 27, respectively. "The coils areenergized by means'. of a transformer 28 which is connected acrossconductors`4 and 5 ofthe primary circuit. In the vicinityof the heatingelements 17,' 18 and 19 in the furnace thermocouples 31, 32 and 33 arelocated which operatc pyronietric control switches 84, 35 and 86,respectively, in the'circuits of the niagnetic switches 25,26 and 27.Whenever the temperature in the vicinity of a given heating elementrises above 4a predetermined value ,the corresponding pyrometric controlswitch willbe opened which willresult in the opening of the switch inthe secondary of the supply circuit until the temperature has dropped toa predetermined value when the switch will again be closed. A seriestransformer 37. is associated :with each of the conductors leading tothe heating ,elements and has in circuit therewith a relay 38 havingnormally lclosed contacts. The relays are arranged in groups of threecomprisingV three groups 41, 42 and 43, and each group is connectedacross the terminals of a coil of the secondary switches 25, 26 and v27,re-

spectively.` The groups 41,42 andl43 have also in circuit therewithrelays 44,45 and 46 of a signal circuit having normally opencontacts.The signal 'circuiticomprisesftwo conductors 47 and 48 which areconnected in par-4 j allel to a bell 49andwa signal lamp 51, and

one of the conductors'has a direct current source ,52 in seriestherewith so that whenever a contact is madeb'etween the two conductorsthe bell and lamp will produce a signal.

Therelays `in circuit with the series transformers may be so adjustedthat when the current in a conductorbecomes. less than a predeterminedamount, the contacts of the relayy associated therewith will bepermitted to close, establishing a circuit through one of the relays'44, 45 and 46 depending upon the group in which the contacts-of theArelay were closed,` thereby closing the signal circuit and producingasignal. It `will be seen that whenever-one of the secondary switches22, 23 "or .24 is opened, the currentV in the corresponding secondaryleads will be interrupted and the contacts of relays associatedtherewith willbe closed. However, the norl mally open relay in thesignal circuit will not the reason that themsecond-v be voperated forsistance contact in the circuit or the burning out of one ofthe heatingelements of the furnace.

The signal circuit is also adapted to be `operated when one of the fusesinthe primary circuit is destroyed. For thispurpose a relay 54 havingnormally open contacts is provided which is connected across theterminals of the fuse 7 in theline 3i. so that when the fuse/in thisline is destroyed the relay will be subjected to the line voltageclosing the relay andv operating the signal circuit. If either of thefuses 8'01 9iis destroyed, the voltage applied to the-transformer 28 isreduced to one-lialf the normal voltage, which is insufficient tooperate a relay 55 causing its normally closed contacts which aremaintained in an open position while the relay is energized to close andoperate the signal circuit. In order to operate the apparatus it ismerely necessary to close theI primary switch 6 and; then close a switch56 inthe signal circuit. The closing of the primary switch will energizethe transformer 28, closing the secondary circuits by means of themagnetic switches. Vhen the transformer 28 is energized, the relay 55 isenergized completely opening the signal circuit until such a change inthe operating conditions of the apparatus occurs as'will causeV asignal.

push button 'switch 57 is provided in the signal circuit to test thesignal devices for the ,purposey of;v determining whether "they are'inproper operatingA condition.

In addition to the series transformers associated with the secondaryleads, a series transformer 60 may be associated with each branch of thedelta connected heating elementsi'n the furnace as shown. It iscustomary to bring the leads of all the heating ele` ments of al furnaceto the exterior and make the delta connection there, so that the seriestransformers may be conveniently connected with each branchof theheating elements of f the furnace. The series transformers when used areConnected in circuit with relays 61 which comprise two groups 62 and 63'which are connected in parallel with groups 42l and 43, respectively.The operation of a relay in group 62` orr63 will therefore have. the

same effect as the operation of a relay in the respectiveparal-lel group42 or 43. v When the additionaltransformers are used the. accurateadjustment of the relays in circuit with the series transformers in thesecondary leads is not necessary and the latter may be so adjusted as toindicate only a complete current failure in the lead.

It will be understood that the embodiment of the invention hereindescribed and illustrated is merely a convenient and: useful form of theinvention which is capable of many other modifications without departingfrom vthe spirit and scope of the invention.

`Whatis claimed is:

1 A signalin system for a supply circuit having aL plura ity of leadsdivided into a plurality of groups, a switch for each group of leads, atransformer associated with each ofthe leads, said transformers beingarranged ingroups correspondingto'I the switches, a signalcircuit, alrelay associated with each group` of transformers yto energize thesignal lcircuit in response to predetermined5 low currentconditions-ina'leadof'that group, and means to prevent the relay from energizingthesignal circuit when the switch of the groupis opened.

2. Aisignaling system for a supply circuit comprising a switch operatedby a magnetic coil, a transformer associated with a lead of the supplycircuit, a signalv circuit connected across the terminals of themagnetic coil-,a relay for operating the signalfcircuit, means forenergizing the relayv when the current in the transformer'decreases to apredetermined lowvalue, and means for preventing an energizati'on offtherelay when the switch is open. 3. A signaling system for a supplycircuit havingk a plurality of supply leads com rising a signal circuit,means for energizing t e signal circuit when. the current inonel of theleads decreases to a predetermined lowy value, andi means for preventingthe energization of the signal circuit when the current in apredetermined number of the leadsisznormally interrupted but causing itsenergization when abnormally interrupted.

4. In a signaling-systemffcr a circuit for supplying a plurality. ofheating devices, a plurality of'supplyleads for each of thefheatingdevices,va signal circuit, means for energizing the signal'circuit whenthe current-iin `oneV of? the leads decreases to a predetermined Ylio-wvalue, and means for'preventing the envmeans for interrupting thecurrent in the leads of one of the heating devices in response totemperature conditions, and means for preventing the energization of thesignal: circuit when the current in the leadsfoffV a heating device isinterrupted in response to temperature erated devices in response topredetermined 10 conditions. conditions, and means for preventing theen- 6. In a signaling system for a circuit for ergization of the signalcircuit in response to supplying a plurality of electrically operatedthe disconnection of the electrically operated devices, a plurality ofleads for each of said device. devices, a signal circuit, means forenergizing In Witness whereof, I hereunto subscribe my 15 the signalcircuit when the current in a lead name this `third day of December A.D. 1926. decreases to a predetermined low value, means for disconnectingone of said electrically op- AUSTIN LE BOUTILLIER.

